The Winklevoss twins famously claimed to have been cheated out of their rightful share of Facebook by Mark Zuckerberg, leading to contentious litigation and a $65 million settlement. They have since become technology venture capitalists and some of the biggest holders of Bitcoin and are planning to launch a publicly traded Bitcoin fund.

In a blog post on the website for Winklevoss Capital, the twins’ technology venture capital firm, Tyler said that Bitcoin and space tourism were “technologies that meaningfully represent our focus at Winklevoss Capital - the reduction of pain-points and friction in an effort to build a better world.” They also called their tickets “seed capital supporting a new technology that may forever change the way we travel, purchased with a new technology that may forever change the way we transact.”

According to Virgin Galactic’s website, one ticket costs $250,000, meaning the Winklevoss’s tickets cost 757.5 bitcoins at today’s prices of $660 for one Bitcoin on Winkdex, a Bitcoin price index introduced by the twins last month.

Tyler wrote that the “desire to build beyond what we have inherited and push beyond our own preconceived barriers” were “responsible for every human breakthrough and advancement since the dawn of mankind.” Including, presumably, Bitcoin.